1. Field of the Invention
The present invention relates in general to integrated circuit dice, and, in particular, to devices and methods for limiting the extent to which circuits in integrated circuit dice load bond pads and other circuit nodes in the dice.
2. State of the Art
Integrated circuit (IC) dice or "chips" are small, generally rectangular electronic devices cut from a semiconductor wafer, such as a silicon wafer, on which multiple ICs have been fabricated. IC dice generally communicate with external circuitry, such as other IC dice, through wire, or tape-automated-bonding (TAB), leads connecting bond pads on the dice to the external circuitry, as shown in U.S. Pat. Nos. 5,252,853 and 5,272,590.
In most IC dice, including Dynamic Random Access Memory (DRAM) IC dice, it is preferable that electronic signals between external circuitry and circuitry on the dice propagate into or out of the dice through the bond pads as quickly as possible. For example, in DRAM IC dice it is preferable that address signals propagate into the dice through the bond pads as quickly as possible, because time spent waiting for the address signals to propagate into the dice slows the response time of the dice to read and write requests.
It is recognized that, in some IC dice, including some DRAM IC dice, there are anomalous differences in the time it takes electronic signals to propagate into or out of similar bond pads on the dice. For example, in the D37M DRAM IC die manufactured by the Assignee of the present invention, Micron Technology, Inc. of Boise, Id., address signals take 1 ns longer to propagate into one address bit bond pad (A9) than any other address bit bond pad. As a result, the response time of the D37M DRAM IC die is slowed by at least 1 ns.
Since it is preferable for electronic signals to propagate into and out of IC dice as quickly as possible, there is a need in the art for a recognition of the reason for the anomalous differences in propagation time described above. There is also a need for a device and method for reducing these anomalous differences in IC dice.